The invention relates to an arrangement for treating patients by means of focussed shock waves, particularly lithotritors, having a therapy head which is fastened by means of an arm to a housing and includes devices for generating, focussing and introducing shock waves into a patient's body, the axis of the therapy head being movable on a conical envelope, the tip of which is situated in the focal point of the therapy head (isocenter). An apparatus of this type is known from the European Patent Document EP 0 286 170.
It is an object of the invention to kinematically improve such an arrangement with respect to the locating, the positioning and the treatment of the patient.
According to the invention, this object is achieved by means of an arrangement wherein the axis of the therapy head is movable on the enclosure of a cone, the tip of which is in the focal point isocenter of the therapy head, and wherein the therapy head is fastened to the arm by means of a gearing mechanism.
The therapy head is arranged in such a manner that it is movable on the envelope of a cone, the tip of the conical envelope coinciding with the focal point of the therapy head (isocentric movement). The envelope of the cone, according to the invention, is situated such that one of its generatrices extends perpendicularly, that is, that the therapy head can also be brought into a position in which its longitudinal axis extends perpendicularly so that the treatment of gallstones also becomes possible.
A gearing swivels the therapy head on the conical envelope in such a manner that it does not carry out any rotation about its longitudinal axis with respect to the overall apparatus. Thus unintentional shifts are avoided when taking up the locating.
In an embodiment of the invention, an ultrasonic locating device is fastened to the therapy head in such a manner that its center axis constantly aims at the focal point of the therapy head. This has the advantage that, in the ultrasonic image, the focal point is always in the center line whereby the locating is significantly simplified. The physician is relatively free to search for windows for the ultrasonic image on the patient's body and in this case does not lose the focus from the center of the image.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.